From b28899ac07be3fb92137ffef7c711655ed39cfcb Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@kastelo.net>
Date: Wed, 25 Mar 2020 14:19:35 +0100
Subject: [PATCH] cmd/ursrv: Provide cached locations.json

---
 cmd/ursrv/main.go | 44 +++++++++++++++++++++++++++++++++++++-------
 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/cmd/ursrv/main.go b/cmd/ursrv/main.go
index e03a250ba..df1ecd121 100644
--- a/cmd/ursrv/main.go
+++ b/cmd/ursrv/main.go
@@ -754,6 +754,7 @@ func main() {
 	http.HandleFunc("/movement.json", withDB(db, movementHandler))
 	http.HandleFunc("/performance.json", withDB(db, performanceHandler))
 	http.HandleFunc("/blockstats.json", withDB(db, blockStatsHandler))
+	http.HandleFunc("/locations.json", withDB(db, locationsHandler))
 	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
 
 	go cacheRefresher(db)
@@ -765,9 +766,10 @@ func main() {
 }
 
 var (
-	cacheData []byte
-	cacheTime time.Time
-	cacheMut  sync.Mutex
+	cachedIndex     []byte
+	cachedLocations []byte
+	cacheTime       time.Time
+	cacheMut        sync.Mutex
 )
 
 const maxCacheTime = 15 * time.Minute
@@ -791,8 +793,15 @@ func refreshCacheLocked(db *sql.DB) error {
 	if err != nil {
 		return err
 	}
-	cacheData = buf.Bytes()
+	cachedIndex = buf.Bytes()
 	cacheTime = time.Now()
+
+	locs := rep["locations"].(map[location]int)
+	wlocs := make([]weightedLocation, 0, len(locs))
+	for loc, w := range locs {
+		wlocs = append(wlocs, weightedLocation{loc, w})
+	}
+	cachedLocations, _ = json.Marshal(wlocs)
 	return nil
 }
 
@@ -810,13 +819,29 @@ func rootHandler(db *sql.DB, w http.ResponseWriter, r *http.Request) {
 		}
 
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
-		w.Write(cacheData)
+		w.Write(cachedIndex)
 	} else {
 		http.Error(w, "Not found", 404)
 		return
 	}
 }
 
+func locationsHandler(db *sql.DB, w http.ResponseWriter, r *http.Request) {
+	cacheMut.Lock()
+	defer cacheMut.Unlock()
+
+	if time.Since(cacheTime) > maxCacheTime {
+		if err := refreshCacheLocked(db); err != nil {
+			log.Println(err)
+			http.Error(w, "Template Error", http.StatusInternalServerError)
+			return
+		}
+	}
+
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.Write(cachedLocations)
+}
+
 func newDataHandler(db *sql.DB, w http.ResponseWriter, r *http.Request) {
 	defer r.Body.Close()
 
@@ -1016,8 +1041,13 @@ func inc(storage map[string]int, key string, i interface{}) {
 }
 
 type location struct {
-	Latitude  float64
-	Longitude float64
+	Latitude  float64 `json:"lat"`
+	Longitude float64 `json:"lon"`
+}
+
+type weightedLocation struct {
+	location
+	Weight int `json:"weight"`
 }
 
 func getReport(db *sql.DB) map[string]interface{} {